Gladstone Alves da Silva

Advances in Glomeromycota taxonomy and classification

Concomitant morphological and molecular analyses have led to major breakthroughs in the taxonomic organization of the phylum Glomeromycota. Fungi in this phylum are known to form arbuscular mycorrhiza, and so far three classes, five orders, 14 families and 29 genera have been described. Sensu lato, spore formation in 10 of the arbuscular mycorrhiza-forming genera is exclusively glomoid, one is gigasporoid, seven are scutellosporoid, four are entrophosporoid, two are acaulosporoid, and one is pacisporoid. Spore bimorphism is found in three genera, and one genus is associated with cyanobacteria. Here we present the current classification developed in several recent publications and provide a summary to facilitate the identification of taxa from genus to class level.

Rhizoglomus, a new genus of the Glomeraceae

Rhizoglomus gen. nov. (Glomeraceae, Glomeromycetes) is proposed, typified by Glomus intraradices [≡ Rhizoglomus intraradices]. The genus encompasses species of arbuscular mycorrhizal fungi that frequently form abundant spores in soil and roots and is morphologically characterized by spores with cylindrical subtending hyphae (usually with an open pore at the base) and at least two or three (rarely up to five) distinct wall layers. Phylogenetically, the genus forms a separate clade in the Glomeraceae. In addition to R. intraradices, the genus includes R. aggregatum, R. antarcticum, R. arabicum, R. clarum, R. custos, R. fasciculatum, R. invermaium, R. irregulare, R. manihotis, R. microaggregatum, R. natalense, and R. proliferum. Some of these species were previously assigned to Rhizophagus (type: R. populinus), a pathogenic genus that does not belong in the Glomeromycota.

Phylogenetic analysis of Glomeromycota by partial LSU rDNA sequences

We analyzed the large subunit ribosomal RNA (rRNA) gene [LSU ribosomal DNA (rDNA)] as a phylogenetic marker for arbuscular mycorrhizal (AM) fungal taxonomy. Partial LSU rDNA sequences were obtained from ten AM fungal isolates, comprising seven species, with two new primers designed for Glomeromycota LSU rDNA. The sequences, together with 58 sequences available from the databases, represented 31 AM fungal species. Neighbor joining and parsimony analyses were performed with the aim of evaluating the potential of the LSU rDNA for phylogenetic resolution. The resulting trees indicated that Archaeosporaceae are a basal group in Glomeromycota, Acaulosporaceae and Gigasporaceae belong to the same clade, while Glomeraceae are polyphyletic. The results support data obtained with the small subunit (SSU) rRNA gene, demonstrating that the LSU rRNA gene is a useful molecular marker for clarifying taxonomic and phylogenetic relationships in Glomeromycota.

Fungal Planet description sheets: 400–468

Novel species of fungi described in the present study include the following from Australia: Vermiculariopsiella eucalypti, Mulderomyces natalis (incl. Mulderomyces gen. nov.), Fusicladium paraamoenum, Neotrimmatostroma paraexcentricum, and Pseudophloeospora eucalyptorum on leaves of Eucalyptus spp., Anungitea grevilleae (on leaves of Grevillea sp.), Pyrenochaeta acaciae (on leaves of Acacia sp.), and Brunneocarpos banksiae (incl. Brunneocarpos gen. nov.) on cones of Banksia attenuata. Novel foliicolous taxa from South Africa include Neosulcatispora strelitziae (on Strelitzia nicolai), Colletotrichum ledebouriae (on Ledebouria floridunda), Cylindrosympodioides brabejum (incl. Cylindrosympodioides gen. nov.) on Brabejum stellatifolium, Sclerostagonospora ericae (on Erica sp.), Setophoma cyperi (on Cyperus sphaerocephala), and Phaeosphaeria breonadiae (on Breonadia microcephala). Novelties described from Robben Island (South Africa) include Wojnowiciella cissampeli and Diaporthe cissampeli (both on Cissampelos capensis), Phaeotheca salicorniae (on Salicornia meyeriana), Paracylindrocarpon aloicola (incl. Paracylindrocarpon gen. nov.) on Aloe sp., and Libertasomyces myopori (incl. Libertasomyces gen. nov.) on Myoporum serratum. Several novelties are recorded from La Réunion (France), namely Phaeosphaeriopsis agapanthi (on Agapanthus sp.), Roussoella solani (on Solanum mauritianum), Vermiculariopsiella acaciae (on Acacia heterophylla), Dothiorella acacicola (on Acacia mearnsii), Chalara clidemiae (on Clidemia hirta), Cytospora tibouchinae (on Tibouchina semidecandra), Diaporthe ocoteae (on Ocotea obtusata), Castanediella eucalypticola, Phaeophleospora eucalypticola and Fusicladium eucalypticola (on Eucalyptus robusta), Lareunionomyces syzygii (incl. Lareunionomyces gen. nov.) and Parawiesneriomyces syzygii (incl. Parawiesneriomyces gen. nov.) on leaves of Syzygium jambos. Novel taxa from the USA include Meristemomyces arctostaphylos (on Arctostaphylos patula), Ochroconis dracaenae (on Dracaena reflexa), Rasamsonia columbiensis (air of a hotel conference room), Paecilomyces tabacinus (on Nicotiana tabacum), Toxicocladosporium hominis (from human broncoalveolar lavage fluid), Nothophoma macrospora (from respiratory secretion of a patient with pneumonia), and Penidiellopsis radicularis (incl. Penidiellopsis gen. nov.) from a human nail. Novel taxa described from Malaysia include Prosopidicola albizziae (on Albizzia falcataria), Proxipyricularia asari (on Asarum sp.), Diaporthe passifloricola (on Passiflora foetida), Paramycoleptodiscus albizziae (incl. Paramycoleptodiscus gen. nov.) on Albizzia falcataria, and Malaysiasca phaii (incl. Malaysiasca gen. nov.) on Phaius reflexipetalus. Two species are newly described from human patients in the Czech Republic, namely Microascus longicollis (from toenails of patient with suspected onychomycosis), and Chrysosporium echinulatum (from sole skin of patient). Furthermore, Alternaria quercicola is described on leaves of Quercus brantii (Iran), Stemphylium beticola on leaves of Beta vulgaris (The Netherlands), Scleroderma capeverdeanum on soil (Cape Verde Islands), Scleroderma dunensis on soil, and Blastobotrys meliponae from bee honey (Brazil), Ganoderma mbrekobenum on angiosperms (Ghana), Geoglossum raitviirii and Entoloma kruticianum on soil (Russia), Priceomyces vitoshaensis on Pterostichus melas (Carabidae) (Bulgaria) is the only one for which the family is listed, Ganoderma ecuadoriense on decaying wood (Ecuador), Thyrostroma cornicola on Cornus officinalis (Korea), Cercophora vinosa on decorticated branch of Salix sp. (France), Coprinus pinetorum, Coprinus littoralis and Xerocomellus poederi on soil (Spain). Two new genera from Colombia include Helminthosporiella and Uwemyces on leaves of Elaeis oleifera. Two species are described from India, namely Russula intervenosa (ectomycorrhizal with Shorea robusta), and Crinipellis odorata (on bark of Mytragyna parviflora). Novelties from Thailand include Cyphellophora gamsii (on leaf litter), Pisolithus aureosericeus and Corynascus citrinus (on soil). Two species are newly described from Citrus in Italy, namely Dendryphiella paravinosa on Citrus sinensis, and Ramularia citricola on Citrus floridana. Morphological and culture characteristics along with ITS nrDNA barcodes are provided for all taxa.

Intraornatosporaceae ( Gigasporales ), a new family with two new genera and two new species

A new family (Intraornatosporaceae), two new genera (Intraornatospora, Paradentiscutata), two new species (P. bahiana, P. maritima), and a new combination (I. intraornata) are presented in the Gigasporales. The genera, both with diagnostic introverted ornamentations on the spore wall, are distinguished by spore wall structure and germ shield characteristics. The new species, detected in NE Brazil, can be differentiated by their projections on the outer spore surface. Partial sequences of the LSU rRNA gene place both species next to I. intraornata in a monophyletic major clade related to Gigasporaceae and Dentiscutataceae.

Arbuscular mycorrhiza in species of Commelinidae (Liliopsida) in the state of Pernambuco (Brazil)

Micorrizas sao associacoes simbioticas mutualisticas formadas entre fungos e raizes de plantas, sendo o principal beneficio para a planta o aumento do aporte de nutrientes. Agronomicamente, a micorriza arbuscular (MA) e o tipo mais importante de micorrizas e apresenta-se distribuido na maioria dos ecossistemas. O objetivo deste trabalho foi estudar a condicao micorrizica de especies de Commelinidae que ocorrem no Estado de Pernambuco. Raizes dessas plantas, coletadas em 10 municipios, foram lavadas, clareadas em KOH, coradas com azul de Tripano em lactoglicerol e observadas em microscopio para determinacao da presenca e identificacao do tipo de micorriza formado. O percentual de colonizacao das raizes foi avaliado pelo metodo de intersecao em placa quadriculada. Quarenta especimens, representando 30 especies, foram observados. Destes especimens, 70% estavam colonizados por fungos micorrizicos arbusculares (FMA). Em uma das familias (Typhaceae) nao foi encontrada a associacao; em duas (Eriocaulaceae e Juncaceae) todos os especimens apresentaram-se micorrizados e tres (Commelinaceae, Cyperaceae e Poaceae) mostraram especimens com ou sem FMA. Em algumas raizes foram observados outros fungos, alem dos micorrizicos. Os resultados indicam que FMA estao amplamente distribuidos entre as especies de Commelinidae em Pernambuco, sendo provavelmente importantes para o estabelecimento das mesmas nas areas de coleta.

Checklist of the arbuscular mycorrhizal fungi (Glomeromycota) in the Brazilian semiarid

Seventy-nine species of arbuscular mycorrhizal fungi (AMF) are reported for the semiarid Caatinga biome of Northeast Brazil. Data are based primarily on research by L.C. Maia and co-workers during the past 20 years. The full checklist is available at www.mycotaxon.com/resources/weblists.html.

Acaulospora pustulata and Acaulospora tortuosa , two new species in the Glomeromycota from Sierra Nevada National Park (southern Spain)

Two new Acaulospora species were found in two wet mountainous grassland ecosystems of Sierra Nevada National Park (Spain), living in the rhizosphere of two endangered plants, Ophioglossum vulgatum and Narcissus nevadensis, which co-occurred with other plants like Holcus lanatus, Trifolium repens, Mentha suaveolens and Carum verticillatum, in soils affected by ground water flow. The two fungi produced spores in pot cultures, using O. vulgatum, N. nevadensis, H. lanatus and T. repens as bait plants. Acaulospora pustulata has a pustulate spore ornamentation similar to that of Diversispora pustulata, while A. tortuosa has surface projections that resemble innumerous hyphae-like structures that are more rudimentary than the hyphae-like structures known for spores of Sacculospora baltica or Glomus tortuosum. Phylogenetic analyses of sequences of the ITS and partial LSU of the ribosomal genes reveal that both fungi are new species within the Acaulosporaceae. They are most closely related to A. alpina and undescribed Acaulospora species. With 45–72 μm spore size, Acaulospora pustulata is the smallest Acaulospora species known so far, while A. tortuosa has slightly larger spores (61–84(–94) μm), which is in the range known for several other Acaulospora species like A. longula, A. alpina, A. nivalis and A. sieverdingii that have either smooth or pitted spore surfaces. These two fungi might play an important role in helping their endangered hosts O. vulgatum and N. nevadensis to survive under the stressed environments of the high mountains of Sierra Nevada.

Bezerromycetales and Wiesneriomycetales ord. nov. (class Dothideomycetes), with two novel genera to accommodate endophytic fungi from Brazilian cactus

During a survey of endophytic fungi from the cactus Tacinga inamoena in a Brazilian tropical dry forest (Caatinga) some undescribed ascomycetous fungi were isolated. These fungi are characterized by superficial and immersed, globose to subglobose, smooth or hairy ascomata, bitunicate asci, and muriformly septate, ellipsoidal ascospores. Multigene phylogenetic analyses using sequences from partial ITS, SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) demonstrated a monophyletic clade accommodating these endophytic fungi in the class Dothideomycetes, closely related to the order Tubeufiales. Based on morphological features and phylogenetic analyses, these fungi could not be placed in the order Tubeufiales, in the new order Wiesneriomycetales, or any other known genus in the class Dothideomycetes. Thus, two new genera (Bezerromyces, with B. brasiliensis and B. pernambucoensis, and Xiliomyces with X. brasiliensis), a new family (Bezerromycetaceae) and a new order (Bezerromycetales) are introduced to accommodate these novel taxa. Our phylogenetic analyses also demonstrated that the clade accommodating Wiesneriomycetaceae represents a new order, here introduced as Wiesneriomycetales.

Paraglomus pernambucanum sp. nov. and Paraglomus bolivianum comb. nov., and biogeographic distribution of Paraglomus and Pacispora

Paraglomus pernambucanum sp. nov. (Paraglomeromycetes) was found in a tropical dry forest in the semi-arid Caatinga biome of Pernambuco State (NE Brazil), in a cowpea and in two maize production sites. It was characterized by combined morphological and molecular analyses on the spores isolated from field soil samples. Another species, Pacispora boliviana (Glomeromycetes), first described only by spore morphology, had been known from another semi-arid biome in Southern America, the Gran Chaco in Bolivia. We detected this fungus now also at different locations in semi-arid to semi-humid NE Brazil. As for P. pernambucanum phylogenetic analyses were performed on nuclear ribosomal RNA gene sequences of the LSU region. For P. boliviana, the spores for these analyses originated from a trap culture inoculated with soils from the type location. The results now revealed that also P. boliviana belongs to Paraglomus. It grouped in a separate monophyletic cluster adjacent to P. pernambucanum, to P. brasilianum, P. laccatum and the type species P. occultum. Thus, P. boliviana is transferred to Paraglomus, as Paraglomus bolivianum comb. nov. Remarkably, it is the first species known in the Paraglomeromycetes with pigmented spores. Paraglomus pernambucanum and P. bolivianum have several features in common: e.g. bi-walled spores, and densely pitted surface ornamentations on the structural layer of the outer wall. Spores of the two species can be distinguished by color and the diagnostic nature of their pitted ornamentation. The current knowledge about the global distribution of Paraglomus and Pacispora species is summarized and discussed.